<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>树</title>
</head>

<body>
    <!DOCTYPE HEML PUBLIC>
    <html>

    <head>
        <meta charset="utf-8">
        <style>
            html,
            body {
                width: 100%;
                height: 100%;
                margin: 0;
                padding: 0;
                border: 0;
            }

            div {
                margin: 0;
                padding: 0;
                border: 0;
            }

            .nav {
                position: absolute;
                top: 0;
                left: 0;
                width: 100%;
                height: 27px;
                background-color: white;
                color: black;
                text-align: center;
                line-height: 25px;
            }

            a {
                color: black;
                text-decoration: none;
                border-bottom: 1px dashed black;
            }

            a:hover {
                border-bottom: 1px solid red;
            }

            .previous {
                float: left;
                margin-left: 10px;
            }

            .next {
                float: right;
                margin-right: 10px;
            }

            .green {
                color: green;
            }

            .red {
                color: red;
            }

            textarea {
                width: 100%;
                height: 100%;
                border: 0;
                padding: 0;
                margin: 0;
                padding-bottom: 20px;
            }

            .block-outer {
                float: left;
                width: 22%;
                height: 100%;
                padding: 5px;
                border-left: 1px solid black;
                margin: 30px 3px 3px 3px;
            }

            .block-inner {
                height: 68%;
            }

            .one {
                border: 0;
            }
        </style>
    </head>

    <body marginwidth="0" marginheight="0">
        <canvas id="c" height="356" width="446">
            <script>
                var collapsed = true;
                function toggle() {
                    var fs = top.document.getElementsByTagName('frameset')[0];
                    var f = fs.getElementsByTagName('frame');
                    if (collapsed) {
                        fs.rows = '250px,*';
                        fs.noResize = false;
                        f[0].noResize = false;
                        f[1].noResize = false;
                    }

                    else {
                        fs.rows = '30px,*';
                        fs.noResize = true;
                        f[0].noResize = true;
                        f[1].noResize = true;
                    }
                    collapsed = !collapsed;
                }
            </script>

            <script>
                var b = document.body;
                var c = document.getElementsByTagName('canvas')[0];
                var a = c.getContext('2d');
                document.body.clientWidth;
            </script>

            <script>
                M = Math;
                Q = M.random; J = [];
                U = 16;
                T = M.sin;
                E = M.sqrt;
                for (O = k = 0; x = z = j = i = k < 200;)
                    with (M[k] = k ? c.cloneNode(0) : c) {
                        width = height = k ? 32 : W = 446;
                        with (getContext('2d'))
                        if (k > 10 | !k)

                            for (
                                font = '60px Impact',
                                V = 'rgba('; I = i * U, fillStyle = k ? k == 13 ? V + '205,205,215,.15)' :
                                    V + (147 + I) + ',' + (k % 2 ? 128 + I : 0) + ',' + I + ',.5)' : '#cca', i < 7;)

                                beginPath(fill(arc(U - i / 3, 24 - i / 2, k == 13 ? 4 - (i++) / 2 : 8 - i++, 0, M.PI * 2, 1)));

                        else for (;
                            x = T(i),
                            y = Q() * 2 - 1,
                            D = x * x + y * y,
                            B = E(D - x / .9 - 1.5 * y + 1),
                            R = 67 * (B + 1) * (L = k / 9 + .8) >> 1,
                            i++ < W;
                        )

                            if (D < 1)
                                beginPath(strokeStyle = V + R + ',' + (R + B * L >> 0) + ',40,.1)'),
                                    moveTo(U + x * 8, U + y * 8),
                                    lineTo(U + x * U, U + y * U),
                                    stroke();

                        for (
                            y = H = k + E(k++) * 25,
                            R = Q() * W;
                            P = 3, j < H;)
                            J[O++] = [
                                x += T(R) * P + Q() * 6 - 3, y += Q() * U - 8,
                                z += T(R - 11) * P + Q() * 6 - 3,
                                j / H * 20 + ((j += U) > H & Q() > .8 ? Q(P = 9) * 4 : 0) >> 1]
                    }

                setInterval(function G(m, l) {
                    A = T(D - 11);
                    if (l)

                        return (
                            m[2] - l[2]) * A + (l[0] - m[0]) * T(D);
                    a.clearRect(0, 0, W, W);
                    J.sort(G);

                    for (
                        i = 0;
                        L = J[i++];
                        a.drawImage(M[L[3] + 1], 207 + L[0] * A + L[2] * T(D) >> 0, L[1] >> 1)) {
                        if (i == 2e3)
                            a.fillText
                                ('Happy Christmas!', U, 345);

                        if (!(i % 7))
                            a.drawImage(M[13],
                                ((157 * (i * i) + T(D * 5 + i * i) * 5) % W) >> 0,
                                ((113 * i + (D * i) / 60) % (290 + i / 99)) >> 0);
                    }
                    D += .02
                }, 1)
            </script>
    </body>

    </html>

</body>

</html>